Exclusive for FAST magazine, March 2005 issue

CAPTIVATING SAVINGS ARE ON OFFER WITH RIVET

BUSHES

By Steve Smith, Sales Director, Northern Precision

The ability of rivet bushes to generate strong and permanent load bearing threads in thin (down to 0.5 mm) sheet metal can generate both financial and ‘manufacturability’ advantages over other types of captivated fasteners like, say, self-clinching fasteners or sheets nuts, in material that is otherwise too thin to be drilled and tapped for component attachment.   Because they are ideally suited to thin panels of any hardness, rivet bushes (unlike self-clinching fasteners that have minimum panel thickness and maximum hardness limitations) do not only allow users to often reduce manufacturing costs by using thinner panels, where appropriate, but production processes can also be streamlined and made more cost-effective because the need for loose nuts and washers is eliminated – along with their associated assembly times and costs.   In addition to providing excellent torque- and pull-out performance, other benefits include:   • The price of rivet bushes compares favourably with other types of captivated fasteners • A flush finish (when using an appropriate profiled anvil) is produced on the reverse side of the panel • Rivet bushes can be installed before or after painting   With all these advantages, it’s no surprise therefore that rivet bushes are increasingly finding widespread appeal throughout the white goods, electronics enclosure, medical, catering, automotive and defence sectors – indeed, in any sheet metal fabrication application that requires a captivated thread.   Installation is simple: the item can be installed using a hydraulic or fly press - even a hammer - though for best performance a hydraulic press with suitably profiled punches is recommended.   Rivet bushes work by having an internally profiled ‘spigot’ that protrudes through the panel just enough to allow for swaging over.   They are available in a range of standard thread sizes to suit specific panel thicknesses as well as a number of head styles – for instance, round, hexagon, mini and closed end (tank style) round and mini standoffs.   Round and mini rivet bushes and rivet bush standoffs are available with knurling either on the spigot or under the body.   Northern Precision’s wide range of standard rivet bushes is available in a wide range of materials (plated and unplated steel, different grades of stainless, aluminium and brass) and can be supplied next-day, or ‘specials’ can be quickly produced to customer specification.   The standard range covers panel thicknesses up to 3 mm thick (10swg), and quantities from 100-off to in excess of a million pieces can be supplied.   Accredited to BS EN ISO 9001:2000, Northern Precision Ltd (www.npfasteners.com) is a specialist single- source supplier of fasteners as well as special-purpose turned and cold-formed parts.   It maintains an extensive variety of 5,000 in-stock standard line items covering most applications and materials. In addition to rivet bushes, the company supplies self-clinching fasteners, bushes, sheet nuts, high- strength and broaching fasteners, weld nuts and studs, cage nuts and blind rivets, as well as special turned and cold-formed components to customer requirements.   Rivet bushes – the Northern Precision guide Standard round knurled shoulder: The shoulder knurling provides excellent resistance to torque in all materials.   Standard round serrated spigot: Dimensionally the same as above but with a serrated spigot. This provides good resistance to torque, especially in softer materials such as aluminium.   Round mini rivet bush: Provides good resistance to torque in limited space.   Hexagon rivet bush: The hexagon pattern provides excellent resistance to torque in all materials. For applications requiring higher than normal bolt tightening loads, a spanner can be used on the bush.   Tank type rivet bush: Closed-ended for applications where the component needs to be sealed against the ingress of air, liquid or dirt or where the incursion of an extra long thread could be potentially damaging, ie fuel and heating systems and electrical enclosures. Very often the fastener is the smallest component part in terms of both size and cost of any finished product, yet it can often create the biggest headache if it is not accurately specified or, indeed, manufactured correctly.   Full technical specifications of Northern Precision’s rivet bushes, and other fastening products, can be found at www.npfasteners.com/rivetbush Issued March 2005 on behalf of: Northern Precision Ltd, Unit 3 Durham Lane, Armthorpe, Doncaster DN3 3FE Tel: 01302 836010 Fax: 01302 836012 Web site: www.npfasteners.com Contact: Mr. Steve Smith, Director of Sales & Marketing Editorial enquiries: sales@npfasteners.com Read other news from 2005